1. FIELD OF THE INVENTION
The present invention generally relates to projectiles and, more particularly, to a fin-bearing stabilized type of projectile.
2. PRIOR ART
Various types of fin-stabilized projectiles, such as missiles, bombs, marking devices, flares and the like have been provided in the past. Certain of such projectiles include fins which move from a collapsed or closed position for storage to an open or deployed stabilizing position. One such device is shown in U.S. Pat. No. 3,374,969. In that patent a projectile which can be fired from a small bore weapon is disclosed. Interlocked spring metallic vanes are held in a closed position by a gun bore and they automatically spring out to form a shrouded fin assembly, once the projectile is launched from the gun bore. The fins assume a spiral or helical configuration within the shroud. Such a device is useful for certain special small gun-fired projectiles but is complicated and impractical for larger projectiles.
A spin-cone stabilized projectile is disclosed in U.S. Pat. No. 3,081,703. Interleaved trapezoidal vanes interlocked at their edges are connected to a projectile and when the projectile is fired, they form a frusto-conical discharge nozzle fanning out behind the rear of the main projectile body and having substantial air drag. U.S. Pat. No. 412,670 is similar in that a plurality of collapsible vanes hinged at their front ends to a shell body spring outwardly when deployed to form a frusto-conical rear stabilizing array with considerable air drag.
U.S. Pat. No. 4,162,053 discloses a braking device for a rotating body such as a load-bearing vehicle ejected from a projectile. The device includes curved, angled vanes or blades which extend to retard both linear and relative movement, thus providing considerable air drag.
There remains a need for an improved type of simple, inexpensive projectile having fins which can be easily closed for storage and as easily deployed for use, which vanes flight-stabilize the projectile while presenting a minimum amount of projectile-slowing air drag.